Q: I have an ASCII file with latitude, longitude and geoidal separation data. How can I use it in NaviSuite software?
Latitude, longitude, geoidal separation
A: Yes, that is possible.
Some manual actions are required though in order to make a VORF type of file from it:
- Open Microsoft Excel and load the txt file. For recent versions of Excel you need to use the legacy importer.
- Add a 4th column for Uncertainty data. This is required when using the VORF format.
See also EIVA Geodesy Manual at chapter 5.2 Geoidal File, https://eiva.freshdesk.com/support/solutions/articles/43000520809-geodetic-control
- Go to the latitude and longitude columns and set the number of decimals to 4.
- Select all columns when sorting, otherwise it will only sort the selected columns.
- Sort the data based on the latitude, longitude columns. Sort from the lower left corner (latitude values ascending, and then for the same latitude value, longitude should be increasing).
As a result you get a file looking like this:
- Export it as a .txt file (tab delimited).
- Change the extension from .txt to .vrf.
- Open eg NaviPac software and load the .vrf file in the Height Reduction window (step 3 on the image below).
It will prompt you to save a .gbin file.
- Test the file in the Test section of the NaviPac Height Reduction window and compare it against your model.
Note, the .gbin file can be used in NaviEdit. You do not need a NaviPac dongle for this operation.